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AM Planetary Gearbox

planetary transmission - Auto | HowStuffWorks

Gears are used in various devices including, but not limited to, automobiles, electric screwdrivers, VCRs and clocks. Automobile transmissions utilize planetary gear arrangements to produce the various gear ratios necessary to drive the automobile. A conventional planetary gear transmission includes a sun gear, planet gears, a planet gear carrier and a ring gear. The output to input gear ratio is then a function of which gear set is selected as the input, output and stationary member.

An example of a planetary gear transmission is described and claimed in U.S. Pat. No. 5,295,925 (the '925 patent) to Hirabayashi. The '925 patent is directed to a two stage planetary gear transmission. The uniqueness of the '925 patent resides in a cantilevered pinion shaft of the second stage that adjusts misalignment or improper meshing of the gears of the first stage and a lubricant layer that adjusts improper meshing of the gears of the second stage.

How Automatic Transmissions Work

A large gear pump to move transmission fluid around

Another example of a planetary gear transmission is described in U.S. Pat. No. 5,098,358 (the '358 patent) to Igaku. The object of the '358 patent is the ability to reduce the cost of manufacturing and assembling while alleviating noise generation of the transmission in practice.

In yet another example of a planetary gear transmission U.S. Pat. No. 4,088,041 (the '041 patent) to Kraus sets forth an energy storing flywheel drive. Two counter rotating flywheels remove the gyroscopic forces. However, typically heavy bearings and strong housing portions are necessary to contain said transmission arrangement. The '041 patent thus describes a new support arrangement to eliminate the use of heavy bearings and strong housing portions.

Consisting of planetary gear sets as well as clutches and bands.

As described above, in the planetary carrier of the planetary gear transmission according to the present invention, the both plate members 32a and 32b can be connected by the rivet 48 under the state that the both planetary gears 28b and 30b are carried by the both plate members 32a and 32b with the both gears meshed each other, wherein the second planetary gear 28b is carried by the boss 50 of the first plate member 32a and the first planetary gear 30b is carried by the bearing holes 58a and 58b.

It should be noted that each of the planetary gear set transmission arrangements shown in can be implemented in a mirrored version similar to that shown in . It should be further noted that the present invention provides that all sun gears are equal in size, all planet gears are equal in size and all ring gears are equal in size providing an input/output ratio by changing the differential input as opposed to relying on scaled-up or scaled-down gear sizes.

Reference is now made to the figures wherein like parts are referred to by like numerals throughout. shows the preferred dual planetary gear set transmission 1A of the present invention including a shaft 10, a differential input 11, input/output means 12, 13, sun gears 14, 15 planet gear carriers 16, 17, planet gears 18, 19, 20, 21 and ring gears 22, 23 in a coupled arrangement denoted as 24. The shaft 10 is grounded by bolts 2 while the differential input 11 is secured by bolts 3. The ratio, regardless of the embodiment practiced, between the input/output means 12, 13 of the transmission 1A is always 1:1 as long as the differential input 11 is at rest. By providing a differential input 11, a proportional differential angle is created between the first gear set and the second gear set (left and right as shown in ). The creation of the differential angle alters the ratio between the input/output means 12, 13.